Tampon applicators comprising a plurality of telescopically-arranged tubes are known. Such applicators are, however, either blunt ended at the end which is intended for vaginal insertion (the "expulsion end") or, in recent years applicators have been developed which are rounded at that end, having a plurality of separated "petals" which are further spaced upon the expulsion through the end of a tampon. The telescopic tube arrangement permits one tube to be used as a plunger to force the expulsion of the tampon from another tube in which the plunger tube is slidably positioned. Although the petal format is more convenient for vaginal insertion, the prior art structures suffer from a number of disadvantages, the most significant of which is probably the tendency of the expanded petal arrangement (after expulsion of a tampon) to catch or nip tissue and hair. By way of example, a petal-type tampon applicator made from plastics material is known in which the rounded tampon expulsion end comprises a number of separated petals integrally formed with the remainder of the upper part of the tampon applicator. The petals each come to a point so that the rounded end, before expulsion of a tampon, is closed and has the appearance in end-on view of a circle split into a number of segments. Unfortunately, the petals of this structure have a tendency to nip or catch tissue or hair therebetween when the applicator is in use this tendency is exacerbated by the petals readily springing back to the original configuration after expulsion of a tampon. Existing long petal arrangements also exhibit a problem which arises from the less stable expulsion end configuration produced by long petals. The resulting less stable formed end may produce user discomfort because of the increased risk of the petals being bent back during vaginal insertion.
Additionally, it has been long recognized that the internal vaginal cavity in its normal collapsed state is of much wider dimension in its transverse plane than in its vertical plane. It is equally well known that the minimum dimension of the vagina is near the introitus while the maximum dimension is near the cervix. It is desirable, therefore, when considering a tampon for catamenial use, to provide a structure which is in its initial state is of a size small enough to pass through the vaginal orifice without discomfort, and when once inside the vaginal cavity and beyond the restrictions of the orifice may be expanded, particularly in the lateral direction, to contact substantially large portions of the vaginal walls, preferably from one side to the other in the vaginal cavity to prevent early bypass of the menstrual discharges from the cervix. Note that this side-to-side coverage is a highly preferred object of this invention. Since the vaginal wall in its normal collapsed state is flaccid and has multiple folds and wrinkles which provide channels through which a significant portion of the menstrual fluids normally flow, it is also important that the absorbent tampon be as soft and conformable as possible in order to conform to the shape of the vaginal cavity and fit within these channels to minimize leakage.
The absorbent catamenial tampons now in general use comprise small, highly compressed, cylindrical plugs about three-eighths to one-half inch (about 1.0 cm to 1.3 cm) in diameter and from 11/2 to 2 1/2 inches in length (about 3.8 cm to 6.4 cm). Because of the need for absorbent capacity, they are usually formed from batts much larger in size than the vaginal orifice, and compressed to the small size indicated above in order to facilitate insertion. As fluid is absorbed, these compressed tampons are expected to re-expand toward their original pre-compressed size, and to eventually become large enough to effectively cover the vaginal cavity against fluid leakage or bypass. While it has been found that these compressed tampons perform their intended function tolerably well, even the best of them do not re-expand sufficiently, or fast enough, to provide good transverse coverage against leakage even though the vertical block may be satisfactory. Further, most of these tampons often use only a small portion of their absorptive capacity before leakage. Since these tampons rely on some fluid absorption to re-expand, it is clear that fluid bypass and leakage can occur prematurely, and can particularly occur immediately or soon after the time of insertion.
Numerous attempts have been made to solve this problem with some approaches focusing on the applicator and others focusing on the tampon itself For example, some approaches in the patent art suggest a tampon with a built-in mechanical expansion means, a typical example being U.S. Pat. No. 3,706,311 to Kohx, et al. However, the mechanical expansion means disclosed in that patent is in the form of a flat spring-like element which after insertion permanently maintains the spread configuration of the tampon, which may make it difficult to remove.
Another approach is described in U.S. Pat. No. 3,512,528 to Whitehead, et al. which teaches the use of a sack of absorbent material collapsed to a small size for insertion and which after insertion is expanded by the introduction of a gas or a fluid internally of the sack. The multiple steps and complicated manipulation of the gas or fluid introduction means required when using this type of tampon detract from the tampon.
Still another approach is described in U.S. Pat. No. 3,857,395 issued to Johnson, et al. The Johnson, et al. patent teaches the use of an elongated inserter device over which a flat tampon is draped. The inserter is said to permit the draped portion of the tampon to be pulled, rather than pushed into the cavity from the point at which the tampon is supported on the leading end of the inserter. The inserter means is equipped with a bilateral expansion mechanism which at the user's option may be operated to transversely spread the tampon at the time of insertion. The inserter device described in the Johnson, et al. patent suffers from many drawbacks, however. The Johnson inserter device is a complicated device comprising a pair of hinged arms that are capable of laterally diverging at a hinge or joint. The angular nature of the hinged arms would make that inserter uncomfortable to use. The complex nature of the hinged arms would also make it difficult and expensive to manufacture. As a result, it would not be suitable as a disposable applicator.
Another problem that exists in deploying tampons having a greater transverse dimension within the vaginal cavity is that this greater transverse dimension of the vaginal cavity is roughly perpendicular to the vaginal opening.
One attempt to address this latter problem is described in U.S. Pat. No. 3,068,867 issued to Bletzinger, et al. The Bletzinger, et al. patent is directed to a tampon insertion device having a positioning indicator thereon. The device described in the Bletzinger, et al. patent comprises an insertion device for tampons which are either of cylindrical cross-section, or non-cylindrical cross-section but constructed to expand when subjected to fluids in a non-cylindrical shape. The insertion device is provided with an indicator that aids the user in inserting the tampon with its major cross-sectional axis transverse to the major axis of the vaginal opening. The Bletzinger device, however, is awkward in that it requires insertion of the widest dimension of the tampon cross-wise to the narrowest dimension of the vaginal opening.
Another series of attempts to overcome the problems associated with conventional, highly compressed, fluid expanding tampons is described in U.S. Pat. No. 3,749,094 issued to Duncan and U.S. Pat. Nos. 3,794,029 and 3,766,921 both issued to Dulle. The Duncan and Dulle devices are all generally conical and are designed to be dry-expanding. While these devices would be expected to overcome some of the problems associated with highly compressed, fluid expanding tampons, the Duncan and Dulle devices still require significant rigidity and compression in order to permit their use in a conventional "tube and plunger" type applicator for which they are designed.
It has been found during development of the present invention that a tampon constructed according to the invention described herein can provide even further improvements in comfort, low wearing awareness, and performance as compared to currently marketed tampons and previous attempts to improve upon such tampons such as those described above.
The present invention aims to provide a structure with the advantages of petal-type applicators, and especially providing for side-to-side coverage, but minimizing the disadvantages noted above.